Negotiation of Quality of Service (QoS) Information for Network Management Traffic in a Wireless Local Area Network (WLAN)

ABSTRACT

An access point advertises a management frame quality of service (MFQ) policy that defines an access category used for transmitting a first type of management frame. Each mobile station associated with the access point is to prioritize transmission of management frames according to the MFQ policy advertised by the access point, unless a policy configuration request for the mobile station to prioritize transmission of management frames according to a different MFQ policy has been accepted.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/460,991 filed Mar. 16, 2017 by Michael Peter Montemurro, etal. entitled, “Negotiation of Quality of Service (QoS) Information forNetwork Management Traffic in a Wireless Local Area Network (WLAN)”(Attorney Docket No. 38102-US-CNT-4214-58513), which is a continuationof U.S. Pat. No. 9,615,383 issued Apr. 4, 2017 entitled, “Negotiation ofQuality of Service (QoS) Information for Network Management Traffic in aWireless Local Area Network (WLAN)” (Attorney Docket No.38102-US-PAT-4214-58501), which claims priority to Canadian PatentApplication No. 2,696,037 filed Mar. 15, 2010 entitled “Advertisementand Dynamic Configuration of WLAN Prioritization States”, all of whichare incorporated by reference herein as if reproduced in theirentireties.

TECHNICAL FIELD

The technology described herein generally relates to wireless local areanetworks (WLANs), and more particularly, to the handling of networkmanagement traffic in a WLAN.

BACKGROUND

The enhanced Distributed Channel Access (EDCA) of the Institute ofElectrical and Electronics Engineers (IEEE) standard 802.11 is anenhancement to the original IEEE 802.11 Media Access Control (MAC)sublayer and is a method of medium access described in the standardamendment document IEEE 802.11e. EDCA provides four prioritized queuesfor transmission, where each queue is associated with a different accesscategory (AC). The four access categories defined, for example, in IEEEstandard 802.11e, in decreasing priority, are AC_VO, AC_VI, AC_BE andAC_BK, named for voice traffic, video traffic, best-effort traffic, andbackground traffic, respectively. The queues use a contention-basedmechanism to determine the next frame for transmission. The queueparameters are set such that the high priority queues have a preferencefor access to the wireless medium.

Management frames are the foundation of network management traffic in aWireless Local Area Network (WLAN). Current IEEE 802.11 standardsdictate that, in any access point (AP) or non-AP station (STA),management frames are to be handled via the EDCA queue of highestpriority.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an example network architecture foradvertisement of management frame QoS (MFQ) information within a basicservice set (BSS);

FIG. 2 is an illustration of an example method to be implemented by anaccess point (AP) for advertisement of MFQ information;

FIG. 3 is an illustration of an example method to be implemented by anAP for including MFQ information in a downlink frame;

FIG. 4 is an illustration of an example method to be implemented by astation (STA) associated with an AP for handling MFQ informationreceived from the AP in a downlink frame;

FIG. 5 is an illustration of example formatting information for a MFQelement;

FIG. 6 is an illustration of an example method to be performed by a STAassociated with an AP for requesting permission from the AP to deviatefrom MFQ information currently advertised by the AP, receiving a policyconfiguration response from the AP, and acting on the received policyconfiguration response;

FIG. 7 is an illustration of an example method to be performed by an APfor receiving a policy configuration request from an associated STA forpermission to deviate from MFQ information currently advertised by theAP and for responding to the policy configuration request;

FIG. 8 is an illustration of example formatting for a policyconfiguration request;

FIG. 9 is an illustration of example formatting for a policyconfiguration response;

FIG. 10 is an illustration of example formatting for a policy stopmessage;

FIG. 11 is a block diagram of an example AP;

FIG. 12 is a block diagram of an example STA;

FIG. 13 is a block diagram of a media access control (MAC) sublayermodule of an AP; and

FIG. 14 is a block diagram of a MAC sublayer module of a STA.

DETAILED DESCRIPTION

The disclosure can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the disclosed technology. Moreover, in the figures,like referenced numerals designate corresponding parts or elementsthroughout the different views. The following description is merelyexemplary in nature and is in no way intended to limit the disclosure,its application, or uses. As used herein, the term “module” refers to anApplication Specific Integrated Circuit (ASIC), an electronic circuit, aprocessor (shared, dedicated, or group) and memory that executes one ormore software or firmware programs stored in the memory, a combinationallogical circuit, and/or other suitable components that provide thedescribed functionality. Herein, the phrase “coupled with” is defined tomean directly connected to or indirectly connected through one or moreintermediate components. Such intermediate components may include bothhardware and software based components.

Recent amendments to the IEEE 802.11 family of standards have increasedthe number and type of management frames, resulting in an increase innetwork management traffic. If all management frames continue to behandled as frames of the highest priority, this may adversely affectoverall network performance or the ability to provide Quality of Service(QoS) to data frames or both. For example, it would not be desirable forthe transmission of diagnostic reports to reduce the quality of a voicecall.

By way of introduction, the disclosure is related to the prioritizationof management frames and are merely exemplary in nature. Moreparticularly, the present disclosure describes the implementation ofprioritization scheme(s) that define various access categories ofdifferent management frames, where each of the access categories isassociated with a respective prioritization used for transmission. Anaccess category may be defined for a group of management frame subtypesor for an individual management frame subtype.

In the present disclosure, access categories AC_BK, AC_BE, AC_VI andAC_VO named for background traffic, best-effort traffic, video traffic,and voice traffic, respectively, are used to illustrate the conceptsdescribed herein. However, it is contemplated that the list of accesscategories may be different. If the list of access categories isdifferent, then the number or definition or both ofaccess-category-dependent queues in a compatible media access control(MAC) sublayer will also be different. An access category is a labelgiven to a common set of enhanced distributed channel access (EDCA)parameters that are used, for example, by a station to contend for achannel in order to transmit information with certain priorities. Inother words, each respective access category (e.g., AC_BK, AC_BE, AC_VIand AC_VO) is associated with (i.e., characterized by or indicative of)a respective priority used for transmission by a station.

Each data frame generated by an application in a non-access point(non-AP) station (STA) already has an indication of its priority. Asused herein, the term “data frame” includes both a content data frameand a signaling data frame. For example, any one or any combination ofthe following values is an example indication of the priority of a dataframe: a user priority assigned to the data frame; the IP-ToS (InternetProtocol-Type of Service) value in an IP header of the data frame; and aDifferentiated Services Code Point (DSCP) value in the IP header of thedata frame. The classification of a data frame to an access category bya MAC sublayer module of a non-AP STA may be based upon the data frame'sindication of priority. For example, data frames having various userpriorities may be classified as follows:

User Priority Access Category 001 AC_BK 010 AC_BK 000 AC_BE 011 AC_BE100 AC_VI 101 AC_VI 110 AC_VO 111 AC_VO

Conventionally, management frames, in contrast to data frames, do nothave an indication of priority, so there is no inherent classificationof a management frame to an access category. Management frames aregenerated within the MAC sublayer module of an AP and/or a STA.

As proposed in the present disclosure, the prioritization schemeincludes a default management frame QoS (MFQ) policy, which is a staticdefinition of access categories for management frames. The default MFQpolicy is implementable by a MAC sublayer module of an AP or non-AP STA.The default MFQ policy is known to all APs and STAs and is therefore notadvertised. An example default MFQ policy includes the followingdefinitions, where the access category of management frames not includedin the following table is AC_BE:

Access Management Frame Subtypes Category Beacon AC_VO (Re)AssociationRequest/Response Probe Request (individually addressed) Probe ResponseAnnouncement Traffic Indication Message (ATIM) DissassociationAuthentication Deauthentication Spectrum management - channel switchannouncement QoS Block Ack Public - extended channel switch announcementPublic - measurement pilot Public - TDLS Discovery Response Fast BSSTransition HT SA Query Protected Dual of Public Action - extendedchannel switch announcement Mesh Action - HWMP Mesh Path Selection AC_VISelf Protected Spectrum Management AC_BE Public Protected Dual of PublicAction WNM Unprotected WNM Mesh Action Multihop Action Vendor-specificProtected Vendor-specific

As proposed in the present disclosure, a MFQ policy will apply to abasic service set (BSS), which comprises an AP and any non-AP STAsassociated with the AP. Therefore, the MFQ policy in effect in one BSSmay differ from the MFQ policy in effect in a different BSS. Inparticular, the MFQ policy in effect in a BSS may differ from thedefault MFQ policy. The MFQ policies in effect in different BSSsbelonging to the same extended service set (ESS) may be identical to oneanother, but this is not necessary. The MFQ policy in effect in a BSSmay change over time. The prioritization scheme for management frames ofthe present disclosure is therefore dynamic in that the prioritizationscheme allows for changes over time in the definition of accesscategories for management frame subtypes.

Furthermore, as proposed herein, the AP of the BSS will determine theMFQ policy that is currently in effect in the BSS and transmitmanagement frames according that policy. The AP advertises MFQinformation that describes how the MFQ policy currently in effect in theBSS differs from the default MFQ policy. Therefore, the MFQ policycurrently in effect in a BSS may be referred to as the advertised MFQpolicy, even though only the differences between the MFQ policycurrently in effect in the BSS and the default MFQ policy areadvertised. An associated STA is therefore informed of the MFQ policycurrently in effect in the BSS through receipt of the advertised MFQinformation.

In accordance with the present disclosure, an associated STA may followthe MFQ policy determined by the AP with which the STA is associated.Alternatively, an associated STA may follow the MFQ policy determined bythe AP with which the STA is associated unless the STA has successfullynegotiated a different MFQ policy with the AP. Compliance of anassociated STA to the advertised MFQ policy or to the negotiated MFQpolicy is not actually checked by the AP with which the STA isassociated, because prioritization of management frames is handledinternally in the STA prior to transmission of the frames.

Advertisement of MFQ Policy by AP

FIG. 1 is an illustration of an example network architecture foradvertisement of MFQ information by an AP of a wireless local areanetwork (WLAN). The WLAN may be configured using IEEE 802.11 technology,and/or or other wireless communication standards including other WLANstandards, personal area network (PAN) standards, wide area network(WAN) standards, or cellular communication standards or networks forproviding wireless network communications.

In the network architecture shown in FIG. 1, a WLAN access point (AP) 10is coupled to a network 12, possibly through a wired communicationinterface, a satellite interface, a Worldwide Interoperability forMicrowave Access (WiMAX®) communication interface, or any other suitablecommunication interface. AP 10 broadcasts beacon frames. Stations 14 areWLAN devices that are within range (i.e., within communication range) ofAP 10 and are associated with AP 10. AP 10 and stations 14 together forma basic service set (BSS) 16. A basic service set identifier (BSSID)identifies BSS 16, and is included in every management frame sent by AP10 or STAs 14. The MAC address of AP 10 is often used as the BSSID. Thenetwork to which BSS 16 belongs is identified by its network name,referred to as a service set identifier (SSID). Unless hidden, the SSIDis included in certain downlink frames, including, for example, beaconframes and probe response frames transmitted by AP 10.

A station (STA) 18 is within range of AP 10 but is not associated withAP 10. STA 18 is therefore not part of the BSS. STA 18 may detect theexistence of AP 10 by undergoing a network discovery process to identifythe available wireless local area networks within range. In someimplementations, the network discovery process includes the receipt bySTA 18 of beacon frames broadcasted by AP 10. In some implementations,the network discovery process includes the transmission by STA 18 of aprobe request frame and receipt by STA 18 of a probe response frame fromAP 10 in response to the probe request frame.

A server 20 is coupled to AP 10 through network 12. In the presentimplementation, server 20 is local to AP 10. Alternatively, server 20may be remote to AP 10, and the coupling of server 20 to AP 10 may occurvia other networks in addition to network 12. For example, if server 20is remote to AP 10, the coupling of server 20 to AP 10 may occur via theInternet.

As explained in further detail in this disclosure, AP 10 advertises MFQinformation that describes how the current MFQ policy in effect in BSS16 differs from the default MFQ policy, and this advertisement may bereceived and interpreted by associated STAs, such as STAs 14, and bynon-associated STAs, such as STA 18. Upon receipt of the advertised MFQpolicy, a classification of management frames of the associated STA maybe adjusted in accordance with the advertised MFQ policy. Anon-associated STA, such as STA 18, may use Access Network QueryProtocol (ANQP) to query an AP, such as AP 10, for the advertised MFQpolicy. For example, a non-associated STA that is actively scanning mayissue a probe request or a Generic Advertisement Service (GAS) requeston an AP's channel in order to determine what MFQ policy the AP isimplementing. However, such a non-associated STA may choose not tofollow that MFQ policy. It should be noted that AP 10 transmitsmanagement frames according the current MFQ policy in effect (i.e.,being implemented) within BSS 16.

FIG. 2 illustrates an example method to be implemented by an AP foradvertisement of MFQ information. At 22, the AP creates an advertisementof MFQ information that describes how the current MFQ policy in effectin the BSS differs from the default MFQ policy. At 24, the AP advertisesthe advertisement, thus advertising the current MFQ policy in effect inthe BSS (i.e., the current MFQ policy). For the sake of simplicity andbrevity, the present disclosure discusses one format of theadvertisement generated by the AP though those skilled in the art willappreciate that other forms of the advertisement are anticipated.

In the example method illustrated in FIG. 3, the advertisement is in theform of a MFQ policy element. The MFQ policy element defines accesscategories of management frames and, as mentioned above, is used toadvertise and exchange MFQ policy between a STA and an AP. The APgenerates a MFQ policy element at 26. At 28, the AP includes the MFQpolicy element in downlink frames, for example, in beacon frames or inprobe response frames or in both. As part of the process of generating abeacon frame and as part of the process of generating a probe responseframe, the AP may regenerate the MFQ policy element to reflect thecurrent MFQ policy in effect in the BSS. The MFQ policy element is notreused from an earlier beacon frame or probe response frame. Rather, theMFQ policy element is generated as part of the process of generating thebeacon frame or probe response frame in which the MFQ policy element isto be included.

An AP may indicate support for management frame prioritization bysetting an appropriate bit, referred to herein as MFQActivated, in theCapabilities field of the Extended Capabilities information element (IE)to a value of 1 or may indicate lack of support for management frameprioritization by setting that bit to a value of 0. One of the currentlyreserved bits of the Capabilities field of the Extended Capabilities IE(as defined in IEEE Std 802.11-2007) may be used for this purpose.Alternatively, presence of the MFQ policy element in the downlink framemay be an indication to STAs receiving the downlink frame that MFQ isenabled, and lack of presence of the MFQ policy element in the downlinkframe may be an indication to STAs receiving the downlink frame thateither the AP sending the downlink frame does not support MFQ, or the APsending the downlink frame supports MFQ and there is no change to thecurrent MFQ policy for the AP to advertise.

When the AP changes its current MFQ policy in effect in the BSS, thechange is communicated in all the beacon frames transmitted during theDelivery Traffic Indication Message (DTIM) interval following the MFQpolicy change. The change may be indicated, for example, by setting achange bit to a value of 1. The change bit may be part of the MFQ policyelement or may be in another part of the beacon frame. Setting thechange bit to 1 in all beacon frames transmitted during the DTIMinterval following the MFQ policy change will ensure that most, if notall, STAs in the BSS will be informed of a change in MFQ policy for theBSS. For example, even if a STA is in an awake state only for beaconframes that includes DTIMs and is not awake to receive other beaconframes, that STA will still be informed of the change in MFQ policy, andtherefore be prompted to check the MFQ policy element in the beaconframe. However, a STA that has set its ReceiveDTIMs parameter to “No”may not receive a beacon frame that informs of a change in MFQ policyfor the BSS.

FIG. 4 illustrates an example method to be implemented by a STAassociated with an AP for handling MFQ information received from the APin a downlink frame. At 30, the STA receives a downlink frame thatincludes a MFQ policy element. At 32, the STA configures itself toimplement the advertised MFQ policy. In other words, the STA configuresitself to implement the default MFQ policy modified by the content ofthe MFQ policy element. As such, the STA assigns an access category toeach management frame according to an access category assignmentindicated in the MFQ policy element (i.e., the advertised MFQ policy).

FIG. 5 illustrates example formatting information for a MFQ policyelement. In order that the advertisement may be received by associatedSTAs and by non-associated STAs, the size of the MFQ policy elementcomplies with any upper limit on the size of an element innon-associated mode. In one implementation, an Element ID field 34 whichis 1 octet in length includes a value indicating that the element is aMFQ policy element. A length field 36 which is also 1 octet in lengthstores the length of the MFQ policy element. The length of the MFQpolicy element may vary, because information for multiple deviationsfrom the default MFQ policy may be included in the MFQ policy element. AMFQ policy info field 38, alternatively named “Access CategoryAssignment Count” field 38, is 1 octet in length and includes a valueindicating the number of deviations which are included in the MFQ policyelement. MFQ policy info field 38 may also include a change bit toindicate whether the MFQ policy has changed. The “Deviation from defaultMFQ policy for management frame subtype #1” field 40, alternativelynamed “Management Prioritization Policy for Category #1” field 40,“Access Category Assignment #1” field 40, or “Access Category Mapping#1” field 40, stores a first deviation to be included in the advertisedMFQ policy. Optionally, additional deviations may be provided in fields42 and 44. Fields 40, 42 and 44 are all of variable length.

Any one or any combination of the following factors may be taken intoaccount when determining a change to a MFQ policy: detection of changesin network conditions, anticipation of changes in network conditions,detection of changes in network loading (at the BSS level or at the ESSlevel or both), anticipation of changes in network loading (at the BSSlevel or at the ESS level or both), detection of changes in AP loading,anticipation of changes in AP loading, the presence or lack of amulti-media stream, detection of changes in a multi-media stream,anticipation of changes in a multi-media stream, and other operatingconditions.

Negotiated MFQ Policy

An associated non-AP STA may negotiate with the AP with which it isassociated in order to deviate from the advertised MFQ policy (i.e., theconfigured MFQ policy). FIG. 6 illustrates an example method to beperformed by a STA associated with an AP for requesting permission fromthe AP to deviate from the advertised MFQ policy, receiving a responsefrom the AP, and acting on the received response.

The method begins at 46 with a STA implementing the MFQ policyconfigured in its MAC sublayer module. At 48, the STA transmits a policyconfiguration request, also referred to herein as an “MFQ Policy ConfigRequest”, to the AP to request a change in the MFQ policy used totransmit management frames between the STA and the AP (i.e., theresponding AP). In other words, a MFQ Policy Config Request is used tonegotiate a change or modification to the MFQ policy between a STA andan AP with which the STA is associated. The MFQ Policy Config Requesttransmitted by the STA includes or indicates a change(s) to the MFQpolicy being implemented. The policy configuration request may betransmitted in response to a triggering event, for example, a networkproblem, application-related diagnostics, or a financial transaction. At50, the STA receives a policy configuration response from the AP.

The policy configuration request (i.e., the MFQ Policy Config Request)includes a MFQ policy element describing how a requested MFQ policydiffers from the default MFQ policy. In other words, the MFQ policyelement indicates a proposed change with reference to the default MFQpolicy. Any one or any combination of the following factors may takeninto account when determining a requested MFQ policy: detection ofchanges in the associated non-AP STA due to diminishing battery powerlevels, anticipation of changes in the associated non-AP STA due todiminishing battery power levels, detection that a current predictedmotion of the non-AP STA will shortly take the non-AP STA out of radiocoverage, so the requested MFQ policy prioritizes signaling frames overa poor link.

If, as shown at 52, a policy configuration response, also referred to asa “MFQ Policy Config Response”, from the AP indicates that a policyconfiguration request has been rejected by the AP (i.e., the proposedchange(s) in the MFQ Policy Config Request has (have) been rejected),the STA that transmitted the request may continue at 46 to transmitmanagement frames in accordance with the MFQ policy configured in itsMAC sublayer module.

In this document, a “negotiated MFQ policy” is a requested MFQ policyrequested in a policy configuration request that has been accepted bythe AP. If, as shown at 54, a policy configuration response receivedfrom the AP indicates that a policy configuration request has beenaccepted by the AP (i.e., the proposed change(s) in the MFQ PolicyConfig Request has (have) been accepted), the STA proceeds at 56 toimplement the negotiated MFQ policy by configuring its MAC sublayermodule to implement the default MFQ policy modified by the content ofthe policy element (i.e., the proposed changes) in the policyconfiguration request that has been accepted. In some implementations,both the STA and the AP may transmit management frames to each other inaccordance with the changes to the MFQ policy that were indicated in theMFQ Policy Config Request. The negotiated MFQ policy applies only to theassociated STA that made the policy configuration request and does notapply to any other STA in the BSS.

At some point following acceptance of a policy configuration request,the AP may send a policy stop message to the STA that made the policyconfiguration request. Alternatively, the STA that made the policyconfiguration request may send a policy stop message to the AP. As longas no policy stop message has been transmitted by the AP to the STA orby the STA to the AP, the STA may continue to implement the negotiatedMFQ policy. However, if the STA determines at 58 that a policy stopmessage has been received from the AP or transmitted by the STA, the STAmay at 60 configure its MAC sublayer module according to the MFQ policycurrently advertised by the AP. The AP may have changed its advertisedMFQ policy during the time that the STA was configured according to thenegotiated MFQ policy. After the STA has at 58 received a policy stopmessage from the AP or transmitted a policy stop message to the AP, theSTA may wait for an advertisement of the MFQ policy currently in effectfor the BSS in order to configure its MAC sublayer module in accordancewith the current advertised MFQ policy.

Optionally, a policy configuration response received from the AP mayindicate that the STA should retry its policy configuration request, asshown at 62. In this case, the policy configuration response may includea suggested MFQ policy (not shown) that the AP might accept uponrequest. At 64, the STA may transmit another policy configurationrequest to the AP. This policy configuration request may be the samepolicy configuration request that was transmitted by the STA at 48, orthis policy configuration request may include a MFQ policy elementreceived from the AP describing a suggested MFQ policy (not shown)suggested by the AP, or this policy configuration request may include adifferent MFQ policy element describing a different MFQ policy than thepreviously requested MFQ policy. After transmitting the other policyconfiguration request to the AP at 64, the STA receives a new policyconfiguration response from the AP at 50.

As an alternative to use of the policy stop message, a STA that nolonger wishes to follow the negotiated MFQ policy may send to itsassociated AP a policy configuration request that includes an MFQ policyelement identical to the MFQ policy element advertised by the associatedAP. It is expected that the AP will accept a policy configurationrequest that is requesting the MFQ policy currently implemented in theBSS.

As an alternative to use of the policy stop message, an AP that wants aSTA to stop following a negotiated MFQ policy may send to the STA apolicy configuration request that includes an MFQ policy elementidentical to the MFQ policy element advertised by the associated AP. Itis expected that the STA will interpret the policy configuration requestas a command from the associated AP to stop following the negotiated MFQpolicy and to begin following the advertised MFQ policy.

FIG. 7 illustrates an example method to be performed by an AP forreceiving a policy configuration request from an associated STA forpermission to deviate from a MFQ policy currently advertised by the APand for responding to the request.

The method begins at 66 when the AP receives a policy configurationrequest from an associated STA. At 68, the AP determines the result ofthe policy configuration request and includes the result in a policyconfiguration response to be transmitted to the STA. For example, the APmay determine to accept the policy configuration request or to rejectthe policy configuration request. Alternatively, the AP may determinethat the STA should retry the policy configuration request. In the casethat the AP determines that the result of the policy configurationrequest is retry, the AP may optionally determine at 69 a suggested MFQpolicy to include in its policy configuration response to the STA. It iscontemplated that such a suggested MFQ policy may be more likely to beaccepted by the AP than the requested MFQ policy in the policyconfiguration request received from the STA at 66.

Following the AP's determination of the result of the policyconfiguration request at 66 and its optional determination (if theresult is retry) of a suggested MFQ policy to describe in a policyconfiguration response at 68, the AP transmits the policy configurationresponse to the STA at 70.

FIG. 8 illustrates example formatting information for a policyconfiguration request. A policy configuration request may be implementedas a particular type of management frame called an action frame. ACategory field 72 which is 1 octet in length is set to a value forpublic action. A Public Action field 73 which is 1 octet in length isset to indicate a policy configuration request frame. A dialog tokenfield 74 which is 1 octet in length is set by the STA to a value toenable the STA to keep track of its policy configuration requests. A MFQpolicy element 76 field describes the particular MFQ policy that isbeing requested.

FIG. 9 illustrates example formatting information for a policyconfiguration response. A policy configuration response may beimplemented as an action frame. Category field 72 is as described abovefor a policy configuration request. A Public Action field 78 which is 1octet in length is set to indicate a policy configuration responseframe. Dialog token field 74 is as described above for a policyconfiguration request and has the same value that was used to identifythe policy configuration request for which this is a response. A ResultCode field 80, alternatively named “Status Code” field 80, includes anindication that the AP accepts or rejects the policy configurationrequest to which the Dialog Token applies or that the STA should retry arequest for a policy. An optional MFQ policy element field 82,applicable when the content of the Result Code field 80 comprises anindication that the STA should retry a request, describes how asuggested MFQ policy differs from the default MFQ policy. The STA mayrequest the suggested MFQ policy in place of the originally requestedMFQ policy.

FIG. 10 illustrates example formatting information for a policy stopmessage. A policy stop message may be implemented as an action frame.Category field 72 is as described above for a policy configurationrequest. A Public Action field 84 which is 1 octet in length is set toindicate a policy stop message. Dialog token field 74 is as describedabove for a policy configuration request and has the same value that wasused to identify the policy configuration request for which this is apolicy stop message.

Implementation of MFQ Policy (Default, Advertised or Negotiated)

An AP or non-AP STA may configure its MAC sublayer module to implementan MFQ policy. The MFQ policy being implemented by the MAC sublayermodule may be the default MFQ policy. Alternatively, the MFQ policybeing implemented by the MAC sublayer module may be the default MFQmodified by an advertised MFQ policy element. Alternatively, the MFQpolicy being implemented by the MAC sublayer module may be the defaultMFQ policy modified by a MFQ policy element in a policy configurationrequest that has been accepted. While a management frame is generatedwithin the MAC sublayer module, the management frame will be assigned toan access category as defined by the MFQ policy, and subsequentlytransmitted, using the respective access category. In the presentimplementation, the management frame is directed, based on its assignedaccess category, to one of four EDCA prioritized queues where each ofthe prioritized queues is associated with a respective access category.As such, in the present implementation, a management frame assigned toAC_VO will be transmitted using a prioritization (i.e., a transmissionpriority) associated with AC_VO, a management frame assigned to AC_VIwill be transmitted using a prioritization associated with AC_VI, amanagement frame assigned to AC_BE will be transmitted using aprioritization associated with AC_BE, and a management frame assigned toAC_BK will be transmitted using a prioritization associated with AC_BK.In other words, each access category (e.g., AC_VO, AC_VI, AC_BE andAC_BK) is indicative of a distinct prioritization (i.e., transmissionpriority) used to transmit a particular type or subtype of managementframe. Handling of the contents of the prioritized queues may followIEEE 802.11 scheduling and transmission rules. For example, a framescheduler schedules frames from the prioritized queues to be passed tothe physical (PHY) sublayer module for transmission over a channel of awireless medium.

FIG. 11 is a block diagram of an example AP 100. AP 10 is an example ofAP 100. AP 100 comprises a processor 102 coupled to a memory 104 and toa communication interface 106. Communication interface 106 may be awired communication interface, a satellite interface, a WorldwideInteroperability for Microwave Access (WiMAX®) communication interface,or any other suitable communication interface. AP 100 also comprises aWLAN interface 108 within a protocol stack 110 that is coupled toprocessor 102. WLAN interface 108 comprises a logical link control (LLC)sublayer module 112, a MAC sublayer module 114 and a PHY sublayer module116. The BSSID of AP 100 is stored in WLAN interface 108, possibly in aregister 118. The SSID of the WLAN supported by AP 100 is stored in WLANinterface 108, possibly in a register 120. MAC sublayer module 114 maybe compatible with IEEE 802.11. AP 100 also comprises an antenna 122coupled to PHY sublayer module 116. Protocol stack 110 may comprisehigher layers 124. ANQP support may be implemented in MAC sublayermodule 114.

Memory 104 may store an operating system 126 to be executed by processor102. Memory 104 may store applications 128 installed in AP 100 to beexecuted by processor 102. Examples of applications 128 include aconfiguration application that enables a WLAN administrator to configureparameters of the WLAN, for example, its SSID and BSSID(s). Memory 104may store code 130 which, when executed by processor 102, results in oneor more of the methods illustrated in FIGS. 2, 3, and 7.

A default MFQ policy 132 is not advertised in the BSS. Depending uponimplementation, default MFQ policy 132 may be stored in WLAN interface108 (as illustrated) or in memory 104. Depending upon implementation, anadvertised MFQ policy 133 currently implemented by WLAN MAC sublayer 114may be stored in WLAN interface 108 (as illustrated) or in memory 104.AP 100 is able to advertise how advertised MFQ policy 133 differs fromdefault MFQ policy 132. AP 100 may optionally store data 134 related toone or more policy configuration requests that have previously beenreceived from one or more associated STAs and related to one or morepolicy configuration responses that have previously been transmitted toone or more associated STAs. Data 134 may be implemented, for example,as records in a table, where the records are maintained on a per-AID(association identifier) basis. Depending upon implementation, data 134may be stored in WLAN interface 108 (as illustrated) or in memory 104.

AP 100 may comprise other elements that, for clarity, are notillustrated in FIG. 11. Similarly, AP 100 may comprise a subset of theelements illustrated in FIG. 11.

FIG. 12 is a block diagram of an example STA, for example, any one ofSTAs 14. An STA 200 comprises a processor 202 coupled to a memory 204and optionally to one or more other wireless communication interfaces206. For example, wireless communication interfaces 206 may comprise ashort-range wireless communication interface such as a wireless personalarea network interface, possibly compatible with the BluetoothSpecification Version 4.0 published 30 Jun. 2010 or its officialsuccessors. In another example, wireless communication interfaces 206may comprise a wireless wide area network (WWAN) interface such as forcellular communications. One or more antennas 208 may be coupled torespective ones of the wireless communication interfaces 206. An antennamay be shared among more than one wireless interface.

STA 200 also comprises a WLAN interface 210 within a protocol stack 212that is coupled to processor 202. WLAN interface 210 comprises a LLCsublayer module 214, a MAC sublayer module 216 and a PHY sublayer module218. MAC sublayer module 216 may be compatible with IEEE 802.11. STA 200also comprises an antenna 220 coupled to PHY sublayer module 218.Protocol stack 212 may comprise higher layers 222.

Memory 204 may store an operating system 224 to be executed by processor202. Memory 204 may store applications 226 installed in STA 200 to beexecuted by processor 202. For example, applications 226 may comprise acontrol application to act on MFQ policy elements received from an AP.In a further example, applications 226 may comprise a Voice overInternet Protocol (VoIP) application. In yet another example,applications 226 may comprise a telephony application. Memory 204 mayalso store data (not shown) used by operating system 224 andapplications 226.

Memory 204 may store one or more WLAN connection profiles 228, eachidentifying a wireless local area network by its SSID, as known in theart.

Memory 204 may store code 230 which, when executed by processor 202,results in one or more of the methods illustrated in FIGS. 4 and 6.Receipt of a downlink frame and handling of MFQ information describingan advertised MFQ policy may be implemented in MAC sublayer module 216.ANQP support may be implemented in MAC sublayer module 216.

A default MFQ policy 232 is not advertised in the BSS. Depending uponimplementation, default MFQ policy 232 may be stored in WLAN interface210 (as illustrated) or in memory 204. Depending upon implementation, aMFQ policy 233 currently implemented by WLAN MAC sublayer 216 may bestored in WLAN interface 210 (as illustrated) or in memory 204. STA 200may optionally store data 234 related to one or more policyconfiguration requests made by the STA and related to one or more policyconfiguration responses received by the STA. STA 200 may store anindication of its requested MFQ policy and then overwrite currentlyimplemented MFQ policy 233 with the negotiated MFQ policy upon receivingacceptance of the policy configuration request.

Memory 204 may store an audio coder-decoder (codec) 238 or a video codec240 or both. STA 200 may comprise an audio input element 242 and anaudio output element 244, both coupled to processor 202. STA 200 maycomprise a video input element 246 and a video output element 248, bothcoupled to processor 202.

STA 200 may comprise a Global Positioning System (GPS) module 250coupled to processor 202.

STA 200 may comprise one or more user input elements 252 coupled toprocessor 202. Examples of user input elements include a keyboard, akeypad, a touchscreen, a joystick, a thumbwheel, a roller, a touchpad, atrackpad, a capacitive touch pad, an optical touch pad, and any othertype of navigation actuator.

STA 200 may comprise one or more user output elements coupled toprocessor 202, of which a display 254 is illustrated. In the event thatdisplay 254 is a touchscreen, it functions also as a user input element.

STA 200 may comprise one or more alert components 256 coupled toprocessor 202, to be activated in order to alert a user, for example, bysounding a buzzer, playing a ringtone, emanating light, or vibrating.

STA 200 may include mechanical interfaces, such as a power connectorjack, a data interface port such as a Universal Serial Bus (USB) port, aheadphone jack, and other mechanical interfaces that are not explicitlyshown.

STA 200 comprises a power pack 258 that provides power to the othercomponents of STA 200.

STA 200 may comprise other elements that, for clarity, are notillustrated in FIG. 12. Similarly, STA 200 may comprise a subset of theelements illustrated in FIG. 12.

FIG. 13 is a block diagram of a MAC sublayer module 300 of an AP, forexample, MAC sublayer module 114 of AP 100. MAC sublayer module 300 usesa management frame generator 302 to generate management frames which aredistributed to different memory queues by a management frameclassification unit 304. Distribution to the different memory queues isdone according to a MFQ policy 306 currently implemented in the BSS towhich the AP belongs. Management frames of the type or types for whichMFQ policy 306 defines the access category AC_VO are routed bymanagement frame classification unit 304 through memory queue 308.Management frames of the type or types for which MFQ policy 306 definesthe access category AC_VI are routed by management frame classificationunit 304 through memory queue 310. Management frames of the type ortypes for which MFQ policy 306 defines the access category AC_BE arerouted by management frame classification unit 304 through memory queue312. Management frames of the type or types for which MFQ policy 306defines the access category AC_BK are routed by management frameclassification unit 304 through memory queue 314. In someimplementations, MFQ policy 306 defines an access category other thanthe AC_VO access category associated with the highest priority queue 308for at least one management frame type.

Data frames (content frames and signaling frames) received at MACsublayer module 300 from an LLC sublayer module (not shown) of the AP,for example, LLC sublayer module 112, may be processed by a packetclassification, fragmentation and encapsulation module 316 in MACsublayer module 300 and then subsequently routed through the same memoryqueues as the management frames.

A scheduler 318 schedules frames from memory queues 308, 310, 312 and314 to be passed to a PHY sublayer module of the AP, for example, PHYsublayer module 116. For example, IEEE 802.11e has separate minimum andmaximum values for each access category. Within each access category, arandom number is generated that represents a wait time as multiplied bya “slot time”. In IEEE 802.11a/g, a slot time is 9 microseconds. Oncethe wireless medium is quiet or unoccupied, a countdown begins beforetransmission. Each count is 9 microseconds in real time. For AC_VO queue308, the countdown begins at a value between 31 and 127. For AC_VI queue310, the countdown begins at a value between 127 and 255. For AC_BEqueue 312, the countdown begins at a value between 255 and 511. ForAC_BK queue 314, the countdown begins at a value between 511 and 1023.If the countdown is interrupted, it is paused until the wireless mediumis once again quiet, and is then resumed from the value at which it waspaused. If the countdowns for different queues begin at the same time,traffic in a higher priority queue will gain access to the wirelessmedium ahead of traffic in a lower priority queue.

MAC sublayer module 300 further comprises a MFQ policy element generator320 which generates a MFQ policy element based on MFQ policy 306. Asdescribed previously, a MFQ policy element may be included in certainmanagement frames generated by management frame generator 302 toadvertise an advertised MFQ policy. For example, a MFQ policy elementgenerated by MFQ policy element generator 320 may be included in adownlink frame such as a beacon frame or a probe response frame that isgenerated by management frame generator 302. It should be noted that,while not explicitly shown, MAC sublayer module 300 may also implementANQP support.

FIG. 14 is a block diagram of a MAC sublayer module 400 of a STA, forexample, MAC sublayer module 216 of STA 200. MAC sublayer module 400uses a management frame generator 402 to generate management frameswhich are distributed to different memory queues by a management framemapping unit 404. Distribution to the different memory queues is doneaccording to a MFQ policy 406. Management frames of the type or typesfor which MFQ policy 406 defines the access category AC_VO are routed bymanagement frame classification unit 404 through memory queue 408.Management frames of the type or types for which MFQ policy 406 definesthe access category AC_VI are routed by management frame classificationunit 404 through memory queue 410. Management frames of the type ortypes for which MFQ policy 406 defines the access category AC_BE arerouted by management frame classification unit 404 through memory queue412. Management frames of the type or types for which MFQ policy 406defines the access category AC_BK are routed by management frameclassification unit 404 through memory queue 414. In someimplementations, MFQ policy 406 defines an access category other thanthe AC_VO access category associated with the highest priority queue 408for at least one management frame type.

It is contemplated that MFQ policy 406 is an advertised MFQ policy. Itis also contemplated that MFQ policy 406 is a negotiated MFQ policyaccepted by an AP with which the STA is associated. It is alsocontemplated that MFQ policy 406 is the default MFQ policy.

Data frames (content frames and signaling frames) received at MACsublayer module 400 from an LLC sublayer module (not shown) of the STA,for example, LLC sublayer module 214, may be processed by a packetclassification, fragmentation and encapsulation module 416 in MACsublayer module 400 and then subsequently routed through the same memoryqueues as the management frames.

A scheduler 418 schedules frames from memory queues 408, 410, 412 and414 to be passed to a PHY sublayer module of the STA, for example, PHYsublayer module 218. For example, IEEE 802.11e has separate minimum andmaximum values for each access category. Within each access category, arandom number is generated that represents a wait time as multiplied bya “slot time”. In IEEE 802.11a/g, a slot time is 9 microseconds. Oncethe wireless medium is quiet or unoccupied, a countdown begins beforetransmission. Each count is 9 microseconds in real time. For AC_VO queue408, the countdown begins at a value between 31 and 127. For AC_VI queue410, the countdown begins at a value between 127 and 255. For AC_BEqueue 412, the countdown begins at a value between 255 and 511. ForAC_BK queue 414, the countdown begins at a value between 511 and 1023.If the countdown is interrupted, it is paused until the wireless mediumis once again quiet, and is then resumed from the value at which it waspaused. If the countdowns for different queues begin at the same time,traffic in a higher priority queue will gain access to the wirelessmedium ahead of traffic in a lower priority queue.

MAC sublayer module 400 further comprises a MFQ policy element generator420 which generates a MFQ policy element based on a requested MFQpolicy. As described previously, the MFQ policy element may be includedin a policy configuration request generated by management framegenerator 402 to negotiate a deviation from an advertised MFQ policy. Itshould be noted that, while not explicitly shown, MAC sublayer module400 may also implement ANQP support.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed:
 1. A method for a wireless station, the methodcomprising: transmitting, to an access point, a management frameaccording to a first default management frame Quality of Service (MFQ)policy, wherein the first default MFQ policy defines first accesscategories (ACs) of different management frames; receiving from theaccess point a second MFQ policy defining second ACs of differentmanagement frames that the AP uses to transmit management frames; anddetermining to either continue using the first default MFQ policy or touse the second MFQ policy to subsequently transmit further managementframes.
 2. The method as claimed in claim 1, wherein the first defaultMFQ policy includes at least one of a Spectrum management frame of an ACfor Best Effort (AC_BE) or a Beacon frame of an AC for Voice (AC_VO). 3.The method as claimed in claim 1, further comprising receiving, from theaccess point, an extended capabilities information element (IE) havingan indication of support for prioritization of management frames.
 4. Themethod as claimed in claim 1, wherein the first default and second MFQpolicies are defined according to the Institute of Electrical andElectronics Engineers (IEEE) standard 802.11.
 5. The method as claimedin claim 1, wherein the second MFQ policy is implemented as a publicaction frame.
 6. A method for an access point, the method comprising:transmitting, to a wireless device, a first management frame accordingto a first default management frame Quality of Service (MFQ) policy ofthe access point, wherein the first default MFQ policy defines firstaccess categories (ACs) of different management frames; and receivingfrom the wireless device a second management frame, wherein the secondmanagement frame is transmitted by the wireless device according toeither the first default MFQ policy of the access point or a second MFQpolicy of the wireless device, and the second MFQ policy defines secondACs of different management frames that the wireless device uses totransmit management frames.
 7. The method as claimed in claim 6, whereinthe first default MFQ policy includes at least one of a Spectrummanagement frame of an AC for Best Effort (AC_BE) or a Beacon frame ofan AC for Voice (AC_VO).
 8. The method as claimed in claim 6, furthercomprising transmitting, to the wireless device, an extendedcapabilities information element (IE) having an indication of supportfor prioritization of management frames.
 9. The method as claimed inclaim 6, wherein the first and second MFQ policies are defined accordingto the Institute of Electrical and Electronics Engineers (IEEE) standard802.11.
 10. The method as claimed in claim 6, wherein the second MFQpolicy is implemented as a public action frame.
 11. A wireless station,comprising: a processor; and memory storing instructions executable bythe processor such that when executed, cause the processor to: transmit,to an access point, a management frame according to a first defaultmanagement frame Quality of Service (MFQ) policy, wherein the firstdefault MFQ policy defines first access categories (ACs) of differentmanagement frames; receive from the access point a second MFQ policydefining second ACs of different management frames that the AP uses totransmit management frames; and determine to either continue using thefirst default MFQ policy or to use the second MFQ policy to subsequentlytransmit further management frames.
 12. The wireless station as claimedin claim 11, wherein the first default MFQ policy includes at least oneof a Spectrum management frame of an AC for Best Effort (AC_BE) or aBeacon frame of an AC for Voice (AC_VO).
 13. The wireless station asclaimed in claim 11, further comprising receiving, from the accesspoint, an extended capabilities information element (IE) having anindication of support for prioritization of management frames.
 14. Thewireless station as claimed in claim 11, wherein the first default andsecond MFQ policies are defined according to the Institute of Electricaland Electronics Engineers (IEEE) standard 802.11.
 15. The wirelessstation as claimed in claim 11, wherein the second MFQ policy isimplemented as a public action frame.
 16. An access point, comprising: aprocessor; and memory storing instructions executable by the processorsuch that when executed, cause the processor to: transmit, to a wirelessdevice, a first management frame according to a first default managementframe Quality of Service (MFQ) policy of the access point, wherein thefirst default MFQ policy defines first access categories (ACs) ofdifferent management frames; and receive from the wireless device asecond management frame, wherein the second management frame istransmitted by the wireless device according to either the first defaultMFQ policy of the access point or a second MFQ policy of the wirelessdevice, and the second MFQ policy defines second ACs of differentmanagement frames that the wireless device uses to transmit managementframes.
 17. The access point as claimed in claim 16, wherein the firstdefault MFQ policy includes at least one of a Spectrum management frameof an AC for Best Effort (AC_BE) or a Beacon frame of an AC for Voice(AC_VO).
 18. The access point as claimed in claim 16, further comprisingtransmitting, to the wireless device, an extended capabilitiesinformation element (IE) having an indication of support forprioritization of management frames.
 19. The access point as claimed inclaim 16, wherein the first and second MFQ policies are definedaccording to the Institute of Electrical and Electronics Engineers(IEEE) standard 802.11.
 20. The access point as claimed in claim 16,wherein the second MFQ policy is implemented as a public action frame.